By incorporating two matched wavelength division multiplexers wdms and a semiconductor optical amplifier soa into a fiber laser cavity, multiwavelength oscillation is established. The second, if we look into a laser gain profile with respect to multi longitudinal mode, each mode has p or s polarization, so that the oscillating beam is mixed with p and s polarization from each other. It includes narrow linewidth ultraviolet laser, 375 nm single longitudinal mode laser system manufactured by crystalaser. The dfb fiber laser consists of a single fiber bragg grating written in a low birefringent rareearth doped fiber. Simultaneous measurement of strain, temperature and. A polymer membrane is employed beneath the prestrained erbiumdoped fiber edf to convert the sound pressure disturbance into axial strain, alter the cavity length, and induce a shift of the. Apr 19, 1994 in order to partially assess the validity of the design criteria required to achieve single mode operation, a fiber laser was designed, constructed, and tested. A multimode fiber laser sensor system for simultaneous measurement of strain and temperature is proposed and demonstrated. Experimental study of temperature correction on single. Static strain measurement it was pointed out earlier that the measurement of static strain involves the measurement of the time taken by the laser light to propagate along the sensing fibre. By measuring the rf beat frequency between the two orthogonal polarized lasing modes and the absolute wavelength of one mode, both strain and temperature can be determined simultaneously to an accuracy of plus or minus 3 mu. A multi longitudinal mode erbiumdoped fiber laser sensor system for simultaneous measurement of strain and temperature is proposed and experimentally demonstrated.
Experiments of fibers under different temperatures and force conditions are carried out. Osa high resolution distributed strain or temperature. Atomic physics seminars history university of virginia. B caused by strain, two fiber based travel range linear stages are used to stretch the fbg sensor gradually, when 25 km smf is utilized for strain measurement. Frequencydivision multiplexing sensing system based on multilongitudinal mode fiber lasers and beat frequency demodulationj. A multi longitudinal mode fiber laser sensor is proposed and experimentally demonstrated base on beat frequency demodulation method. Abstractin this work, a novel singlelongitudinalmode slm fourwavelength laser.
Your organization subscribes to the spie digital library. A novel laser cavity is formed by a fbg, a section of erbiumdoped fiber and a broadband reflector. Airclad photonic crystal fibers for highpower single. Aoc has designed a new to can package while maintaining excellent mechanical, optical, and thermal characteristics at a competitive cost. Multilongitudinal mode fiberring laser sensor for strain. In simplified terms, a fiber bragg grating is a microstructure typically a few millimeters long created by modifying a standard single mode telecom fiber, germaniumdoped. Features fast measurement and dynamic measurement uses standard telecom single mode fiber good spatial resolution and long range immune to attenuation changes performance at a glance. Osa multimode fiber laser for simultaneous measurement. A 1550 nm multilongitudinal mode laser from ortel corporation amplified with an erbium doped fiber amplifier is used for the twophoton offresonance excitation. The fbg controls the number of laser modes which excited by laser sensor.
The fiber used in this test was optically equivalent to standard telecommunication fiber, allowing for lowcost, highdensity strain measurements on large structures. Because of the temperature effect of the distributed strain observation, it is not easy to analyze the real strain in tested data. The development is reported of a multilongitudinal mode fiber laser sensor based on passive mode locking employing carbon nanotubes in the laser cavity. If multilongitudinal mode fiber laser sensors can realize multiplexing, the cost of each sensor will further reduce, which will greatly promote its application. A multi longitudinal mode laser pulse consists of numerous temporal spikes, making a measurement of the power at the instant of breakdown nearly impossible. Optical fiber sensors for temperature and strain measurement. A multilongitudinal mode fiber laser sensor is proposed and experimentally demonstrated base on beat frequency demodulation method. Single frequency laser single longitudinal mode laser. Pdf a multimode fiber laser sensor system for simultaneous measurement of.
A multiplexed multi longitudinal mode fiber laser sensor system is proposed and demonstrated. Fbg interrogations based on several kinds of fiber lasers. Jun, 2014 this paper experimentally demonstrated a singlemodecorelesssinglemode scs fiber structurebased fiber ring cavity laser for strain and temperature measurement. Because of the absence of a mode selecting device, the mode spacings between multi longitudinal modes in the laser can be large. Polarimetric heterodyning fiber laser sensor for directional. The fiber was doped at approximately 550 ppm, had a 1. The ability of a bragg grating fiber optic sensor to measure longitudinal strain in a fiber is well documented udd 1990, culshawdakin 198897, kersey et al 1997, hill and meltz 1997, measures 2001, and such sensors have found increasing use for monitoring surface strains in mechanical components and civil structures. Measurement science and technology calibration of a single mode polymer optical fiber large strain sensor to cite this article. A longitudinal mode of a resonant cavity is a particular standing wave pattern formed by waves confined in the cavity. Singlemode erbium fiber dualring laser with 60nm workable. Feb 28, 2012 we have demonstrated a highpower singlewavelength, single longitudinal mode fiber laser. The longitudinal modes correspond to the wavelengths of the wave which are reinforced by constructive interference after many reflections from the cavitys reflecting surfaces.
The freerunning mode shows the main noise frequency band of the laser. Tunable singlelongitudinalmode highpower fiber laser. Ansys simulating analysis of 3d singlecable temperature. Strain and hightemperature discrimination using a type ii. Due to its arbitrary output wavelength by choosing the pump laser wavelength. Dts0115 fiber optic distributed strain and temperature. Depending on the application, fiber may be used because of its small size, or because no electrical power is needed at the. A novel laser cavity is formed by a fbg, a section of erbium. Calibration of a singlemode polymer optical fiber large. Application note an22 designing with the aoc 10gbps tosa. Airclad photonic crystal fibers hold promise to bring the single mode power levels past the 1kw limit through the utilization of extremely high numerical apertures, large mode field diameters and short fiber lengths. But their reported sensors were not beneficial for the acoustic detection due to the unstable multilongitudinalmode beating signal outputs.
Multilongitudinalmode microlaser model springerlink. A sensing system for simultaneously measuring strain and temperature is proposed by employing a polarimetric multilongitudinal mode fiber laser sensor and beat frequency demodulation device. Fiber sensor systems based on fiber laser and microwave. Calibration and testing of distributed fiber optic sensors. Multilongitudinal mode fiber laser sensor for temperature measurement.
This paper presents an overview of hybrid fiber optic sensing systems based on scattering techniques, fiber bragg gratings, interferometric techniques, and polarimetric methods in structural health monitoring. Simultaneous strain and temperature measurement using a. The polarimetric heterodyning fiber laser sensor, first demonstrated by kim et al. They are equally important as wavelength selective reflectors for fiber, and to a lesser extent, semiconductor lasers. Fiber ring laser sensor for temperature measurement osa. For most of our measurements we used a single laser pulse to damage the sample. In this sensing system, the scs fiber structure not only acts as. Pdf polarimetric distributed feedback fiber laser sensor. The longitudinal mode beat frequency lmbf demodulation can be used to deal with strain or temperature signal 7, 8, while the polarimetric mode beat frequency pmbf generated by fiber birefringence have been applicable for measurements of lateral stress, hydrostatic pressure, directional force and acoustic signal. Figure 4 shows relative intensity noise as measured by a fft spectrum analyzer with dc to 102. Reliability of stable fiber bragg grating sensor system. Dts0127 fiber optic distributed temperature sensors bdts.
Simultaneous measurement of strain and temperature with a multilongitudinal mode erbiumdoped fiber laser l gao, l huang, l chen, x chen optics communications 297, 98101, 20. Interferometry with pulse broadened diode laser carl zeiss. Simultaneous measurement of strain and temperature with a multi longitudinal mode erbiumdoped fiber laser l gao, l huang, l chen, x chen optics communications 297, 98101, 20. Multilongitudinal mode fiberoptic vibration sensor request pdf.
A lowcost fdm system for multilongitudinal mode fiber laser sensor arrayj. Underground power transmission cable connector temperature realtime online measurement system cn104764471a en 20140102. The strain and temperature can be obtained by monitoring both of them for. The frequency comb simultaneously provides excellent spectral resolution and broad wavelength coverage across the visible and near infrared. Nonequilibrium thermal effects and carrier density effects can create small changes in refractive index of the laser cavity. We show that measuring the change in the speckle pattern induced by a change in. Multimodes fiber ring laser sensor combining one fiber bragg. We provide linear stability analysis, and show characteristic spatiotemporal dynamics in such multi longitudinal mode laser models. The laser was free from mode hopping to a maximum output power of 300 mw. Radiofrequency rf beat frequencies between two longitudinal modes and two polarization. A novel multilongitudinalmode fiber ring laser temperature sensor based on the beat frequency demodulation technology is presented. Department of electrical and computer engineering, university. The theory of beat signal generation and strain measurement are discussed in detail. Dfb fiber laser sensor for simultaneous strain and.
Osa quantitative strain sensing in a multimode fiber. Optical fiber sensors for temperature and strain measurement by dapeng zhou a thesis presented to the university of waterloo in ful. Passively modelocked fiber laser sensor for acoustic. Recently, fabryperot interferometers fpis based on an in fiber air cavity were proved to be outstanding in lots of sensing applications, such as strain measurements 12,14,15,16,17,18,19. Multimodes fiber ring laser sensor combining one fiber. Osa multiplexed multilongitudinal mode fiber laser sensor. Fiber bragggratingbased laser sensor, proceedings of spie. A method and device for sensing spatial variations andor temperature variations in the locality of a fiber optic cable 1 is disclosed, wherein a broadband light source 47 is used to shine incident light onto a series of fiber bragg gratings contained within zones a, b and c.
Lband multiwavelength singlelongitudinal mode fiber laser for. We have theoretically analyzed the mode beat mechanism of this laser sensor, which is verified by the experimental observation, and its application in strain measurement has also been studied. Distributedfeedback fiber laser sensor for simultaneous strain. The optical signaltonoise ratio of the laser output is around 70 db. Additional channels can be added by using an external optical switch. Compared to traditional electrical strain gauges, optical strain gauges. Distributed fiber optic strain measurement using rayleigh.
Cn2715111y multichannel optical fiber grating sensor. Osa multilongitudinal mode fiber laser sensor system. Each wavelength corresponding to one channel of wdms contains multi longitudinal modes. A multilongitudinal mode fiber ring laser sensor is proposed and experimentally demonstrated by measuring the strain applied on the laser sensor head.
Abstracta sensing system for simultaneously measuring strain and temperature is proposed by employing a polarimetric multi longitudinal mode fiber laser. Fiber bragg gratings are attracting increasing attention as sensors for the measurement of strain, temperature, and pressure. A stabilized single mode, linearly polarized, erbiumdoped fiber laser with an unique structure of doublecavities is presented. The rayleighbased sensor probes the fiber with pulses of alternating optical frequency and records the backscattered speckle patterns on a highspeed camera. Algorithm development for acoustic emission measurement in highfrequency ranges and its application on a large twostroke marine diesel engine xuan thin dong, manh hung nguyen, donchool lee in press, journal preproof, available online 7 may 2020.
Multilongitudinal mode fiber laser for strain measurement. Simultaneous measurement of strain and temperature with a. In simplified terms, a fiber bragg grating is a microstructure typically a few millimeters long created by modifying a standard single mode telecom fiber, germaniumdoped, with a uv laser. Proceedings paper a 16channel multilongitudinal mode fiber laser sensor array system based on wavelengthfrequency division multiplexing. Novel fiber bragg grating demodulation method and system thereof based on multilongitudinal mode fp laser device cn103630264a en 201204. A multi longitudinal mode fiber laser sensor mlmfls system with high signaltonoise ratio snr is proposed. In a linear cavity, the spatialhole burning shb is eliminated to prevent multi longitudinal mode oscillation by using. A novel method for simultaneous measurement of strain and high temperature using a type ii fiber bragg grating fbg and a miniature fiber fabryperot interferometer mffpi is proposed. Single longitudinal mode pumped optical waveguide laser. Gain, stability, efficiency, life, fb versus dfb laser factors affecting laser resonator performance the following is the short list of physical characteristics of a conventional fabryperot lasing medium between mirrors laser resonator that can affect lasing performance including power output, efficiency, beam quality, and stability. A 16channel multilongitudinal mode fiber laser sensor.
The utilization of fiber lasers for fiber optic sensors multi plexing has attracted. The laser sensor consists of a narrowband fiber bragg grating fbg, erbiumdoped fiber edf and an optical reflector. Optical fiber strain gauges that are based on fiber bragg gratings fbgs operate on very different principles than those that govern traditional electrical strain gauges. A fiber optic sensor is a sensor that uses optical fiber either as the sensing element intrinsic sensors, or as a means of relaying signals from a remote sensor to the electronics that process the signals extrinsic sensors. Oct 23, 2018 a 16channel multi longitudinal mode fiber laser sensor array system based on wavelengthfrequency division multiplexing yunxin hu, zhiyong han, xiujuan yu, xuefeng chen, jintao zhang, shengchun liu.
Multi longitudinal mode fiber laser based displacement days ago we use cookies to offer you a better experience, personalize content, tailor advertising, provide social media features, and better understand the use of our services. We have demonstrated a highpower singlewavelength, singlelongitudinal mode fiber laser. The core component of the system is a multilongitudinal mode fiber ring cavity laser sensor based on beat frequency demodulation method. The method is used to measure strain in a fourstrand multimode cable under twist.
A cfrp was designed and fabricated with a distributed optical fiber strain sensor woven between the plies of the carbon fiber fabric. Polarimetric multilongitudinal mode fiber laser for. To make this measurement, some form of modulation must be applied to the laser source, 2 t e iu uuuu u ill u v u ulu uuuu yi u vuuvv u u v u wu u1 i. In the experiment, six different beat frequency signals are. In this study, a fourchannel frequency division multiplexing fdm multilongitudinal mode fiber ring laser mmfrl sensor array, based on the bf demodulation technology, is proposed. Intrinsic mechanism for spectral evolution in single. Bragg grating strain gage rosettes have also been developed measures et. It was found that the temperature effect of the distributed strain is. The basis of the sensing system is the multimodal interference occurs in coreless fiber, and the transmission spectrum is sensitive to the ambient perturbation. Overview of fiber optic sensor technologies for strain. The core component of the system is a multi longitudinal mode fiber ring cavity laser sensor based on beat frequency demodulation method. Pdf multimode fiber laser for simultaneous measurement of strain. Arion laser oscillating in multi longitudinal modes k. The decision to maintain a to can based infrastructure allows for a lower total cost by leveraging the significant manufacturing infrastructure.
To the best of authors knowledge, this is the highest snr ever reported by mlmfls system. The different types of fos reported for strain temperature measurements in composite materials are fiber bragg grating fbg sensors 35,36,37, interferometric fiber optic sensors, polarimetric sensors, fiber optic micro bend sensors, distributed sensors using techniques such as rayleigh scattering, raman scattering, and brillouin. We report the development of an optical fiber sensor capable of simultaneously measuring strain, temperature and refractive index. Oct 19, 2017 we derive a convenient model for broad aperture microlasers, such as microchip lasers, broad area semiconductor lasers, or vcsels, taking into account several longitudinal mode families. Ultrashort distributed bragg reflector fiber lasers for.
The ring cavity of the laser is formed by a 3db coupler, a section of erbiumdoped fiber, and one fiber bragg grating. Sep, 2018 such multi longitudinal mode laser spectra can be blurred over time by forcing the comb spectrum to shift slightly during the measurement period so that the comb peaks move to fill in the spaces in between the peaks. We report an amplitude measuring multimode fiber sensor capable of making quantitative strain measurements and extracting the algebraic sign of the strain. Fbg wavelength demodulation based on bandwidth of radio. This paper experimentally demonstrated a singlemodecorelesssinglemode scs fiber structurebased fiber ring cavity laser for strain and temperature measurement. This paper describes results from a hybrid laser comprising of a semiconductor optical amplifier coupled to a bragg grating, and investigates the. Multi longitudinal mode beat frequency fiber laser displacement. A multilongitudinal mode fiber laser sensor mlmfls system with high signaltonoise ratio snr is proposed.
Research progress in the key device and technology for fiber. A sensing system for simultaneously measuring strain and temperature is proposed by employing a polarimetric multi longitudinal mode fiber laser sensor and beat frequency demodulation device. Simultaneous strain and temperature measurement using a superstructure fiber bragg grating baiou guan, hwayaw tam, member, ieee, xiaoming tao, and xiaoyi dong abstract a novel and simple fiber optic sensor based on a superstructure fiber bragg grating sfbg for simultaneous strain and temperature measurement is proposed and demonstrated. The laser was tunable over 1565 nm to 1575 nm and had a linewidth of 9 mhz. All other wavelengths are suppressed by destructive interference. Here we discuss design, fabrication and handling issues of such fibers. Raman fiber laser rfl is a specific type of fiber laser based on the gain of stimulated raman scattering srs effect. A multiparameter bragg grating fiber optic sensor and. Polarimetric multilongitudinal mode fiber laser for simultaneous. A sensing system for simultaneously measuring strain and temperature is proposed by employing a polarimetric multilongitudinal mode fiber. The mffpi is produced by fusion splicing a short section of quartz capillary tube with two single mode fibers, and then it is exposed by a focused femtosecond. In this experiment, the laser beam are first collimated and then focused tightly to a beam waist of order 1 m. Pdf multiplexed multilongitudinal mode fiber laser sensor.
Because of the long cavity and birefringence, longitudinal mode beat frequency and polarization mode beat frequency are achieved in the beat frequency signals of the multimode fiber laser. Optical strain gauges also called fiber optical strain sensors or fos, optical strain sensors or fiber bragg grating sensors are used to measure strain, but can easily be integrated into different types of transducers, such as in temperature, acceleration or displacement. The fbg controls the number of laser modes which excited by laser. Osa multilongitudinal mode fiber laser sensor system with. Moreover, we derive the coupled mode model in the presence of intracavity. Single longitudinal mode laser and single frequency lasers, narrow linewidth laser and the laser with long coherence length or single frequency lasers are for the application of raman spectrum, holographics, interferometry. Multilongitudinal mode fiber laser for highlysensitive. Feb 01, 20 a simple fiber ring laser is used for sensing based on beat frequency demodulation.
Pdf passively modelocked multilongitudinal mode fiber. Multilongitudinal mode fiber laser sensor combining the. The beat frequency signal of the laser shifts with both strain and temperature, while, the output power of the laser only changes with temperature because of the erbiumdoped fiber. Each wavelength corresponding to one channel of wdms contains multilongitudinal modes. We present an ultrashort distributed bragg reflector fiber laser photowritten in eryb codoped fiber.
Simultaneous measurement of strain and temperature with a multilongitudinal mode erbiumdoped fiber laser opt. Fiber optic distributed temperature sensors b dts lowcost brillouin botda scattering version photo. Search the leading research in optics and photonics applied research from spie journals, conference proceedings and presentations, and ebooks. Request pdf multilongitudinal mode fiberoptic vibration sensor a novel multilongitudinal. Multimode fiber laser for simultaneous measurement of strain and temperature based on beat frequency demodulation. Study on a fourchannel multilongitudinal mode fiberring. Multiplexed multilongitudinal mode fiber laser sensor. The beat frequency shift caused by the strain applied on the cavity is demodulated using spectrum analyze. A multiplexed multilongitudinal mode fiber laser sensor system is proposed and demonstrated.
Laser output power stabilization for direct laser writing. Singlemode erbium fiber dualring laser with 60nm workable wavelength tunability optics and laser technology 114 2019 1619 contents lists available at sciencedirect optics and laser technology journal homepage. The presence of sa inside the cavity increased the stability of the laser. We describe the use of sweptwavelength interferometry for distributed fiber optic strain and temperature sensing in single mode and gradient index multimode fiber. Oct 20, 2014 a multiplexed multi longitudinal mode fiber laser sensor system is proposed and demonstrated. The measuring principle of multi longitudinal mode beat sensor was described, and strain gage was designed and built.
Therefore, the beat frequency signals with high frequency are generated, and the high sensitivities will be achieved. Reliability of stable fiber bragg grating sensor system for. An optical frequency comb based on the output of a mode locked femtosecond laser can be a valuable tool in a variety of spectroscopic studies and applications. The experiment confirms the potential of embedded fiber optic distributed sensing to be used for realtime health monitoring, or as a process feedback in an instrumented. Related content validation of a single mode polymer optical fiber sensor and interrogator for large strain.
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